Patent Literature 1 describes a laser projection apparatus as a projection display that projects an image onto a screen. This laser projection apparatus has a red laser light source, a blue laser light source, a green laser light source, and a heat dissipating unit. The heat dissipating unit dissipates heat within a casing of the laser projection apparatus to the outside by discharging cooling water into the casing. The cooling water, which is discharged from the heat dissipating unit, removes heat from the blue laser light source and the green laser light source after the red laser light source is cooled down, and returns back to the heat dissipating unit. As described above, since the cooling water removes heat from the red laser light source prior to the blue laser light source and the green laser light source, the temperature of the red laser light source is kept low.
Patent Literature 2 describes a multi-coaxial-laser light source apparatus. The multi-coaxial-laser light source apparatus includes: a collimator lens; a semiconductor laser array that has three light emitting points; pulse lighting control means for selectively performing pulse lighting at the light emitting points; and relative position control means for changing relative positions of the collimator lens and the semiconductor laser array. The relative position control means controls the relative positions of the collimator lens and the semiconductor laser array such that the optical axis of the collimator lens is positioned on the optical axis of each laser light which is emitted through the pulse lighting in accordance with the timing of pulse lighting. Each laser light is converted into parallel light through the collimator lens, and the optical axis of each laser light is substantially the same in a part in which passage areas of the laser light beams overlap.
Patent Literature 3 describes a planar illumination apparatus. The planar illumination apparatus includes: a laser light source that emits three-color laser light beams with different wavelengths; a fiber which has one end, from which three-color laser light beams are incident, and the other end from which the laser light is emitted as emitted light; and a transmission optical member that converts the emitted light into planar illumination light. The multiple laser light beams are incident to one end of the fiber at different NA values according to wavelengths different from each other.